SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'a583bd04a7c2311f7b21ad9a7313c17e00d93d25be5ba440a1947a260fb08134' 
  AND token = 'cY5Hp3/ZVk6FbSMnMUIMXOaK8Yd6DyDlMEILuVccTwU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}